**5.7 Building the gas holder**

A wood or steel structure in form of umbrella is built, and then a mesh network is relayed on the umbrella structure (Figs. 14 and 15). The air supported double membrane cover, which includes the gas holder, is mounted over the structure. The flexible membrane of the gas collector, i.e. holder, moves up and down as a function of the gas pressure. On the other hand, the storage tank covers are numerous: (1) closed cover (concrete, plastic, and tent), (2) straw cover, (3) granulate (perlite), (4) swimming vinyl covering, and (5) open as open lagoons and open storage tanks.

Fig. 14. Wood structure and mesh network that supports the gas holder of digester in a commercial biogas plant (MT-ENERGIE GmbH & Co. KG)

A wood or steel structure in form of umbrella is built, and then a mesh network is relayed on the umbrella structure (Figs. 14 and 15). The air supported double membrane cover, which includes the gas holder, is mounted over the structure. The flexible membrane of the gas collector, i.e. holder, moves up and down as a function of the gas pressure. On the other hand, the storage tank covers are numerous: (1) closed cover (concrete, plastic, and tent), (2) straw cover, (3) granulate (perlite), (4) swimming vinyl covering, and (5) open as open

Fig. 14. Wood structure and mesh network that supports the gas holder of digester in a

commercial biogas plant (MT-ENERGIE GmbH & Co. KG)

Fig. 13. Integrating the heating tubes (BIOGAS NORD GmbH)

**5.7 Building the gas holder** 

lagoons and open storage tanks.

Fig. 15. Mesh network that supports the gas holder of a household unit
